The purpose of this proposal is to relate certain basic biochemical parameters of human cataracts to their microanatomical and morphological characteristics, as specified by the CCRG classification. Specifically, for individual human cataracts, we are studying the chemistry of the non-protein chromophoric constituents, the fiber membrane stability, and protein-protein and protein-lipid interactions at the membrane level. How these parameters differ in various types of cataracts and in opaque and highly pigmented areas of cataractous human lenses will be related to the classification of the cataracts. Variations in these biochemical parameters in cataracts, whose etiology may involve chronic or acute exposure of the eyes of humans to near-UV light, are to be sought. Standard biochemical and photobiological or photochemical techniques, as is outlined in our published and other papers, will be employed. The Prophet System computer will be used to record, analyze and share data with the CCRG wich will be examined and classified from stereophotographs of fresh human cataracts, as elaborated by the CCRG. It is anticipated that biochemical and morphological features of cataracts that are related to human exposure to near-UV light will result from this study.